Operation Astonia was the codename for the Allied effort to capture the German-held Channel port of Le Havre, France, during World War II. Fought from 10-12 September 1944, its objective was to secure the fortress city's harbor facilities intact to aid the Allied supply system on the Continent. However, due to extensive damage the port was not ready for use until mid October 1944, a partial tactical failure.

Considered one of the strongest fortifications in the Atlantic Wall, Le Havre was also aided by strong natural defences that included bodies of water preventing access from the south, east and west.[2] The north side of the port was heavily fortified, with a 6–7-metre (20–23 ft) deep and 3-metre (9.8 ft) wide anti-tank ditch stretching across the entire approach, pillboxes fitted with anti-tank and machine guns and 1,500 mines.[2] Intelligence before the attack estimated there were between 7,300 and 8,700 soldiers in the city, of which 4,000 were artillery troops, 1,300 were naval personnel and the rest a mixture of low-quality infantry and a battalion from the recently constituted 36th Grenadier Regiment[2] formed out of the survivors of the 36th Infantry Division after its destruction at Bobruysk in Belarus in June 1944.

Plans called for a massive naval and air bombardment to soften up the fortifications. Two Royal Navy vessels, the battleship HMS Warspite and the monitorHMS Erebus, bombarded the port with more than 4,000 long tons (4,100 t) of shells over several days.[4] In addition, aircraft of the Royal Air Force dropped 8,200 long tons (8,300 t) of high explosive bombs on the city between September 5 and September 7. [2]

Crews of Churchill tanks watch the RAF bombing the defences of Le Havre, 10 September 1944

The attack plan was to penetrate the German defences to allow further forces to attack, then further these gains and capture the city. An assault of two divisions began at 1745 hours on 10 September, with both naval bombardment vessels engaging the coastal batteries defending the port and RAF bombers dropping an additional 5,000 long tons (5,100 t) of bombs ninety minutes prior to commencing.[5]

The attack on German defences continued into the second day with support from various aircraft and armoured vehicles; facing the threat of Churchill Crocodile flame throwing tanks, the last outer defence strongpoints finally surrendered at 1400 hours. On the third day of the assault the town centre was finally cleared by elements of both divisions, forcing the German garrison commander's official surrender at 1145, 12 September; 12,000 German troops were captured and interned as prisoners of war.[2][5]

While there had been few military casualties during Le Havre's successful capture, from a tactical standpoint the action was a partial failure. Damage to infrastructure was severe: the artillery and air assaults had destroyed 350 vessels, 18 kilometres (11 mi) of docks, and 15,000 buildings, significantly reducing the usefulness of the city as a supply port.[2] Civilian loss was also high, but had been avoidable.

British officer William Douglas-Home was imprisoned for his refusal to participate in the operation after his superiors spurned the German garrison commander Hermann-Eberhard Wildermuth's request to evacuate civilians before the assault. Faced with the Allied policy of unconditional surrender, Colonel Wildermuth had been ordered by Hitler to defend Fortress Le Havre to the last man. Recognizing an indiscriminate pre-assault aerial bombardment would kill many innocent Frenchmen he appealed to British humanity, and reiterated his offer even after the bombing campaign started. Loss of French life was extensive, with some 2,000 dead to 19 Germans lost during the air campaign alone.

Delafoce, Patrick (1999) [1995]. The Polar Bears: Monty's Left Flank: From Normandy to the Relief of Holland with the 49th Division. Chancellor Press. ISBN0-7537-0265-7.

Ellis, Major L.F. (2004) [1st. pub. HMSO:1968]. Butler, Sir James, ed. Victory in the West, Volume II: The Defeat of Germany. History of the Second World War, United Kingdom Military Series. Uckfield, UK: Naval & Military Press. ISBN1-84574-059-9.